A simple REDUCE/STACK combo with an added HSTACK and EXPAND functions added to accomplish the offset and bring it all together:

=IFNA(
    DROP(
        REDUCE(
            "",
            SEQUENCE(ROWS(A2:A6)),
            LAMBDA(a,v, VSTACK(a, HSTACK(EXPAND(0,,INDEX(A2:A6,v),0), CHOOSEROWS(C2:N6, v))))
        ),
        1
    ),
    0
)